In a traditional imaging configuration, it is mainly formed by a set of optical elements, in order from the object side: an input object, two conventional lenses, and a CCD camera. In contrast to the traditional scheme, many other methods with an extra scattering lens [1]}, [2]}, [3]}, [4]} have been proposed for the high-resolution imaging in the past decades. According to the location of the scattering lens in the optical circuit, these schemes can be roughly divided into two categories: (I) behind the object [2]}, [3]} (i.e. between the object and the conventional lens, corresponding to the wide-field imaging) and (II) in front of the object [1]} (in respect of the narrow-field imaging). It is worth pointing out that in case (I), the light behind the object would transport through the scattering lens while in case (II), the light illuminating the object is generated from the scattering lens. Although these two kinds of schemes show optical circuits with the different structures, both of them can realize an image with the enhanced resolution. This is because the scattering lens made of randomly distributed nanoparticles could increase the effective numerical aperture [1]}, [2]}.
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